TF-3591 Implement CalendarEventCounter/accept method

model/lib/extensions/session_extension.dart

@@ -130,6 +130,14 @@ extension SessionExtension on Session {
     return (isAvailable: capability != null, calendarEventCapability: capability);
   }
 
+  bool validateAcceptCounterCalendarEventCapability(AccountId accountId) {
+    final capability = getCapabilityProperties<CalendarEventCapability>(
+      accountId,
+      CapabilityIdentifier.jamesCalendarEvent);
+
+    return capability?.counterSupport == true;
+  }
+
   String? getLanguageForCalendarEvent(
     Locale locale,
     AccountId accountId,

model/pubspec.lock

@@ -645,10 +645,10 @@ packages:
     description:
       path: "."
       ref: main
-      resolved-ref: "708658c13e013882fde91c5afba886bd67641f8f"
+      resolved-ref: "131bdbb2fb5ed268b8c8469d532f70b42ac4e15a"
       url: "https://github.com/linagora/jmap-dart-client.git"
     source: git
-    version: "0.3.3"
+    version: "0.3.4"
   js:
     dependency: transitive
     description: